Low income and poor health tend to go hand in hand — that’s not a particularly surprising or new statement. However, according to family medicine doctor Steven Woolf, we have yet to truly grasp the extent to which income shapes a person’s health and opportunity to live a long life. And if we don’t confront the widening income inequality gap, he says things will only get worse.

“There’s a general awareness that people who have poor education or low incomes have worse health outcomes, but our sense is that we don’t really appreciate the magnitude of the problem,” Woolf told me. “Every time I look at these data, I am still stunned at how dramatic the differences are.”

Woolf, who serves as director of the Center on Society and Health at Virginia Commonwealth University and is a professor in the Department of Family Medicine and Population Health, recently co-authored a series of reports on the connections between income, education and health under the umbrella of two related efforts: The Education and Health Initiative and the Income and Health Initiative. This week, Woolf and his colleagues released two new reports, “How Are Income and Wealth Linked to Health and Longevity?” and “Can Income-Related Policies Improve Population Health?” Woolf said while both reports don’t necessarily contain new information, they were specifically designed to “connect the dots and help the public and policymakers appreciate the fact that decisions about the economy and jobs have big implications not only for the health of Americans, but also for the rising cost of health care.”

“It’s not like we as a society are ignoring the economy,” Woolf said. “But whichever approach you take, we have to understand that there are implications for health and for health care costs.”

The greater one’s income, the lower one’s likelihood of disease and premature death. Studies show that Americans at all income levels are less healthy than those with incomes higher than their own. Not only is income (the earnings and other money acquired each year) associated with better health, but wealth (net worth and assets) affects health as well.

Though it is easy to imagine how health is tied to income for the very poor or the very rich, the relationship between income and health is a gradient: they are connected step-wise at every level of the economic ladder. Middle-class Americans are healthier than those living in or near poverty, but they are less healthy than the upper class. Even wealthy Americans are less healthy than those Americans with higher incomes.

In a table illustrating the burden of various diseases by income in 2011, the differences are striking. For example, 8.1 percent of adults with an annual family income of less than $35,000 have coronary heart disease, compared to 4.9 percent of adults with an annual family income of $100,000 or more; 11 percent of adults in the less than $35,000 category have diabetes, compared to 5.9 percent of adults in the $100,000 or more category; 3 percent of adults in the less than $35,000 category have kidney disease, compared to 0.9 percent of adults in the $100,000 or more category; and 11.6 percent of adults in the less than $35,000 category have no teeth, compared to 4.1 percent of adults in the $100,000 or more category. Children living in low-income families face higher rates of disease as well — more asthma, more hearing problems, more heart conditions and higher blood lead levels — all of which affect their opportunity to do well in school and heightens their risk of poor health in adulthood.

Income is linked with life expectancy as well. The report tells us that by age 25, Americans in the highest income group can expect to live about six years longer than their poorer peers. Woolf tells me that such income differences explain many of the documented health disparities among U.S. racial and ethnic groups. He said: “Even after we adjust for other factors, (income and education) account for a huge part — it’s really about the life circumstances people face.”

So, how exactly do income and wealth impact a person’s health? The first and probably most obvious answer is access to health care. People with low incomes are less able to afford health care services, health insurance, co-payments, deductibles and medicines (though the Affordable Care Act is aimed at removing or lessening the access obstacle). But the health-income association is bigger than access to health care; the report argues that those with higher incomes also enjoy the benefits of healthier community assets. The report states:

People with higher incomes are more likely to experience place-based health benefits, meaning that their health is positively influenced by the conditions and assets in their living environment. In other words, even after adjusting for income and other attributes of individuals and households, health benefits appear to be associated with where people reside. …

The socioeconomic status of individuals and neighborhoods are intertwined with individual and population health because the local economy determines access to jobs, commerce, schools, and other resources that enable families to enjoy economic success and place-based health benefits. For example, one study found that “healthy adults residing in socioeconomically deprived neighborhoods died at a higher rate than did people in relatively less deprived areas, even after accounting for individual-level socioeconomic status, lifestyle practices, and medical history.” Smoking, diabetes, and other conditions are more common for people living in poor neighborhoods, independent of their income.

Along with the health and longevity report, the Income and Health Initiative also released “Can Income-Related Policies Improve Population Health?” That report explores ways to reduce income-related obstacles to better health through three types of policies: those that address early childhood, those that provide income support, and those that improve community and neighborhood conditions. Within these categories, the report addresses a variety of specific policies, such as the Earned Income Tax Credit and the Supplemental Nutrition Assistance Program as well as private and public sector efforts to improve community conditions, such building affordable housing or developing safe recreational areas for children. However, no intervention “seems more promising than education, especially early childhood education,” the report stated.

As a physician, Woolf told me that clinical interventions often have marginal impacts when compared to the effects of social determinants. For example, rates of diabetes — a growing and major source of suffering and cost within the health care system — are about twice as high among low-income people than among those with higher incomes.

“So it stands to reason that the economic burden of treating the disease could be substantially lowered if these people had better economic circumstances,” he said. “Of all the things we do for diabetes in the clinic, we’re not often thinking about how to help people with their educational and economic circumstances…that would probably save more lives than what we do at the bedside.”

So, if income and education are key to better health and lower health care costs, what can physicians and public health practitioners do? First, Woolf said be aware of the connections when working with patients and clients. (“I tell my students that if they don’t understand where their patients live or what kind of economic challenges they’re facing, they can’t expect their clinical plans to produce good outcomes,” he said.) Second, get active in your community — help fellow residents and decision-makers understand that while decisions about education and economic development may not seem connected to health on the surface, such decisions have a direct impact on people’s health and on health care costs. At the national level, do a better job of packaging the data in a way that resonates with policymakers, he said.

While taking to the streets certainly has a role in driving meaningful social change, Woolf said scientists may be most helpful by sticking to and advocating for the science.

“The social justice arguments are very important to many of us, but they don’t always move the needle in the policy world,” he said. “Other kinds of arguments are now taking center stage, like analyses by major economists…showing that income inequality has reached a point that’s so severe that it’s undermining our economy and putting America at a competitive disadvantage. …We live in a cynical society where we need to point out those particular arguments to get the attention of policymakers.”

To download all the reports from the two initiatives, including a series of reports on the economic and health benefits of investing in education, visit the Center on Society and Health.

Kim Krisberg is a freelance public health writer living in Austin, Texas, and has been writing about public health for more than a decade.

Kim Krisberg is a freelance public health reporter living in Austin, Texas, and has been writing about public health for more than 15 years. Follow me on Twitter — @kkrisberg — or send me story ideas at kkrisberg@yahoo.com.